28 km north east of Hama; it is located at a vital crossing point on the Orontes. The settlement has classical origins, local legends recorded by Diodorus Siculus (first century BC) claiming its foundation by a regiment of Thessalonians cavalry from Alexander's forces.

In the early Arab period, a Fatimid castle stood on the site but was seized by the Byzantines in their effort to reassert their control in Syria against the Fatimids. As the Byzantines hold weakened, a local clan seized Shaizar in 1081. By the time the Crusaders had installed themselves briefly in Qalaat Madiq to the north, the clansmen used Shaizar as a base to harass their presence.

Shaizar grew in importance as a center of Arab resistance, so much so that the Crusaders set up positions in the mountains on the opposite side of the plain to observe and contain Shaizar. The Byzantines attempted in 1134 and 1138 to take the castle but failed. Much of it was destroyed in 1157 by the severe earthquake which affected the greater part of Syria. The Crusaders tried to profit from the decimation of the clan owners in the destruction by moving on Shaizar, occupying the lower citadel. But by then Nūr al Din was active in northern Syria. He expelled them, repaired the damage and installed his own governor.

In 1170 another earthquake did further damage. Saladin's incorporation of northern Syria after 1174 brought it under his control. A new keep was constructed under the Ayyūbids (1233). The first Mongol invasion of Syria in 1260 brought renewed destruction but Baybars (1260 - 77) who did much to revive Syria after the Mongol wave has passed, garrisoned it.

Sultan Baybars the Mameluke and his successor, Qalaun, were probably responsible for the substantive rebuilding of a good deal of the castle as seen today. The castle fell into disuse as a military post but came to shelter the village inhabitants whose building activities helped erode its fabric until they were moved out in recent decades.